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3-Phase Induction Motor
What is double-revolving theory? Draw equivalent circuit of 1-phase Induction motor for (i) Running and (ii)
Starting conditions
Draw the phasor diagram and equivalent circuit of a 3-phase induction motor.
Explain how rotating magnetic field is produced in 3-phase induction motor
Explain Equivalent circuit of 3-phase IM with Phasor diagram.
Explain performance of 3-phase I.M. for change in supply frequency with Constant supply voltage.
Explain effect of unequal supply voltage on performance of 3-phase I.M.
Derive the condition of max. torque of Induction Motor. Also explain factors affecting max. Torque condition.
Explain how by inserting resistance in the rotor circuit of a slip ring induction motor the starting current of the
motor can be limited.
State different methods of speed control of 3- _ Induction motor. Explain any one method of speed control of 3- _
slip ring induction motor from the rotor side.
Why starter is necessary for starting a 3-phase Induction motor. Discuss any two types of AC motor starters.
Explain the working, equivalent circuit and advantages of double squirrel cage induction motor.
Discuss different methods of speed control of 3–phase Induction motor.
How is high starting torque obtained by deep bar and double cage rotor construction? Describe their construction.
Also draw the equivalent circuit diagram of double cage Squirrel cage induction motor
Differentiate between harmonic induction torque and harmonic synchronous torque developed in a induction
motor. what are their effects
How can an induction generator feed power into a constant frequency bus?
Give circuit configuration only. Also draw approximate equivalent circuit diagram and phasor diagram of
induction generator.
Discuss how the speed and power factor of a schrage motor can be varied by an emf injected into its secondary
winding. Compare the frequency of the emf induced in and injected into secondary winding.
Define acceleration time. Derive its expression using normal notations of moment of inertia (J), optimum slip for
minimum acceleration time (Smax,opt) etc.
Explain principle, advantage and application of linear induction motor.
Compare linear induction motor and conventional induction motors
Explain principle of magnetic levitation.
Explain the phenomenon of cogging and crawling in induction motor
Write different starters used for 3 phase induction motor and explain any one of them
state the difference between DOL starter and Star-delta starter.
Explain the automatic Y/ Δ starter for 3-phase induction motor using power and control circuit.
Explain the importance of Circle diagram of Polyphase Induction Motor.